Field of the Invention
The present invention relates to an electrical connecting module including: a first electrical connector having a first housing; and a second electrical connector having a second housing, the first and second housing being fit into each other to thereby cause a cylindrical terminal fixed to the first housing and a contact terminal housed in a terminal space formed in the second housing to contact each other.
Description of the Related Art
A kind of electrical connector (such as a connector to be equipped in a glow plug acting as an ignitor or a pre-heating plug in an engine, and a connector used for connecting a combustion pressure sensor to a wire harness) generally includes a cylindrical male connector. Since the male connector is designed to be rotation-symmetric with a female connector, the male connector can be fit into the female connector, even if the male connector is caused to rotate around an axis thereof in either direction. Accordingly, the male connector can be readily fit into the female connector even if it is manually handled in the darkness.
The kind of electrical connector as mentioned above generally includes an elastic contact piece having a contact portion through which the elastic contact piece contacts a cylindrical terminal.
FIG. 32 is a perspective view of a conventional electrical connector disclosed in Japanese Patent Application Laid-open on No. 1997-35825. The illustrated electrical connector includes: a plug connector 1000; and a receptacle connector 1010.
The plug connector 1000 includes: a cylindrical plug insulator 1001; and a plurality of contacts 1002 arranged on an outer surface of the plug insulator 1001 such that a distance from a distal end of the plug insulator 1001 to each of the contacts 1002 is different from others. The receptacle connector 1010 is formed with a hole 1011 into which the plug connector 1000 can be fit. The receptacle connector 1010 includes a plurality of circular receptacle contacts 1012 formed on an inner surface of the hole 1011.
Each of the circular receptacle contacts 1012 is constituted of a thin plate having a lead. Each of the circular receptacle contacts 1012 has an inner diameter smaller than a diameter of the hole 1011.
FIG. 33 is a perspective view of the contact 1002. The contact 1002 is in shape of an arc, and is formed thereon centrally with a bead 1002a. The bead 1002a makes point-contact at a top thereof with the receptacle contact 1012 of the receptacle connector 1010.
FIG. 34 is a perspective view of an electrical connector disclosed in Japanese Patent Application Laid-open on No. 2007-521181, and FIG. 35 is a cross-sectional view of the same.
The illustrated electrical connector includes: a connector 1110 and; an inflator 1120. The inflator 1120 is operated by the connector 1110, and includes an initiator (not shown) having a single center pin 1122, and a receptor 1121 in which the connector 1110 is held.
The connector 1110 includes a plurality of ribs 1111 to be in mesh with a spline 1123 arranged in the receptor 1121. The ribs 1111 allow the connector 1110 to be engaged with the receptor 1121 at a plurality of angles, and prevent the connector 1110 from rotating relative to the inflator 1120 after the connector 1110 has been assembled with the inflator 1120.
When the connector 1110 is connected with the inflator 1120, a shaft portion of a head of the connector 1110 contacts a cylindrical skirt of a header eyelet 1124, and further electrically connects the cylindrical skirt of the header eyelet 1124 with the center pin 1122 which is in the form of a needle.
Apart from the conventional electrical connectors illustrated in FIGS. 32 to 35, there is a known electrical connector including: a first electrical connector having a first housing; and a second electrical connector having a second housing. A cylindrical terminal arranged in the first housing and an elastic contact piece housed in a contact terminal arranged in the second housing contact each other when the first and second electrical connectors are fit into each other.
The cylindrical terminal is fabricated by rounding an electrically conductive sheet, and joining opposite ends of the sheet to each other such that the sheet defines a circle.
When the first and second housings are fit into each other, the elastic contact piece may contact an area through which the opposite ends of the sheet are joined to each other. The area is formed with a step or steps when the opposite ends of the sheet are joined to each other. Accordingly, the contact terminal may be scratched or damaged by the step/steps when the first and second housings are fit into each other.
Furthermore, if one of the first and second electrical connectors rotates around an axis thereof due to oscillation and/or impact while the first and second electrical connectors are being fit into each other, the contact terminal slides on the above-mentioned area, resulting in that the contact terminal may be worn out and/or deformed. Thus, it is afraid that there occurs defectiveness in electrical connection between the first and second electrical connectors.